全文获取类型
收费全文 | 992篇 |
免费 | 18篇 |
专业分类
电工技术 | 40篇 |
综合类 | 1篇 |
化学工业 | 276篇 |
金属工艺 | 18篇 |
机械仪表 | 9篇 |
建筑科学 | 19篇 |
能源动力 | 14篇 |
轻工业 | 61篇 |
水利工程 | 2篇 |
无线电 | 107篇 |
一般工业技术 | 168篇 |
冶金工业 | 232篇 |
原子能技术 | 10篇 |
自动化技术 | 53篇 |
出版年
2022年 | 10篇 |
2021年 | 15篇 |
2019年 | 7篇 |
2018年 | 10篇 |
2017年 | 9篇 |
2016年 | 12篇 |
2015年 | 8篇 |
2014年 | 6篇 |
2013年 | 37篇 |
2012年 | 14篇 |
2011年 | 39篇 |
2010年 | 24篇 |
2009年 | 28篇 |
2008年 | 33篇 |
2007年 | 26篇 |
2006年 | 25篇 |
2005年 | 33篇 |
2004年 | 26篇 |
2003年 | 25篇 |
2002年 | 27篇 |
2001年 | 18篇 |
2000年 | 22篇 |
1999年 | 25篇 |
1998年 | 114篇 |
1997年 | 44篇 |
1996年 | 41篇 |
1995年 | 41篇 |
1994年 | 37篇 |
1993年 | 32篇 |
1992年 | 25篇 |
1991年 | 21篇 |
1990年 | 13篇 |
1989年 | 12篇 |
1988年 | 19篇 |
1987年 | 11篇 |
1986年 | 10篇 |
1985年 | 7篇 |
1983年 | 8篇 |
1982年 | 9篇 |
1981年 | 9篇 |
1980年 | 10篇 |
1979年 | 10篇 |
1978年 | 5篇 |
1977年 | 11篇 |
1976年 | 8篇 |
1975年 | 8篇 |
1972年 | 4篇 |
1971年 | 3篇 |
1970年 | 5篇 |
1969年 | 3篇 |
排序方式: 共有1010条查询结果,搜索用时 15 毫秒
81.
Murilo Santhiago Phabyanno Rodrigues Lima Wilney de Jesus Rodrigues Santos Adriano Bof de Oliveira Lauro T. Kubota 《Electrochimica acta》2009,54(26):6609-6616
The activation of 3,5-dinitrobenzoic acid (3,5-DNBA) in situ is proposed for electrocatalytic detection of NADH at low overpotentials. Thus, 3,5-DNBA was strategically connected to a nanostructured surface based on MWCNTs and PEI (an amine rich polymer). Then, R–NO/R–NHOH was electrogenerated in situ by cycling the potential between 0.15 and −0.55 V versus SCE. The formation of an intermediate charge transfer complex is proposed for the reaction between NADH and redox mediator. The apparent Michaelis–Menten constant (KM) obtained by RDE voltammetry and amperometry was in good agreement, around 10−5 mol L−1. The kobs for the catalytic reaction evaluated by chronoamperometry and RDE voltammetry, was in good agreement and was found to be around 104 L mol−1 s−1. The sensor provides a linear response range for NADH from 4.0 up to 42.0 μmol L−1 with a sensitivity of 71 nA L μmol−1, detection and quantification limits of 1.2 and 4.0 μmol L−1 respectively, with a response time of 0.16 s. 相似文献
82.
R. Kubota K. Kiyokawa M. Arazoe H. Ito Y. Iijima H. Matsushima H. Shimokawa 《Cognition, Technology & Work》2001,3(2):67-81
This report analyses the results of the human error classification scheme of CREAM applied to organisation-committed human
errors related to six departments. These human errors were not caused by the tasks spotlighted by CREAM, but were concentrated
on managerial or administrative tasks, so that the authors have corrected and analysed the definitions and links of cause–effect
relations related to the large organisation by means of an extended method of CREAM. Considering human errors on the basis
of these analyses, findings have allowed the authors to come up with effective relations between organisation-related causal
factors and person-related ones. This has demonstrated that organisation-caused human errors are sufficiently analysable by
means of the extended method of CREAM. 相似文献
83.
In a distribution system containing a step voltage regulator (SVR), the maximum capacity of distributed generators (DGs) is calculated for DGs completely dispersed on a distribution line. The maximum capacity of the DGs is calculated under the constraint of an upper or lower voltage regulation value and an allowable current value by using voltage and current profiles expressed analytically in terms of our proposed power density model. As the voltage control method for the SVRs, we consider the conventional SVR, whose transformation ratio is fixed to 1 if it detects reverse power flow, and a reverse power flow SVR which operates appropriately even if it detects reverse power flow. Calculation of the maximum capacity of DGs with respect to the power factor of the DGs indicates which parameters, including the power factor of the DGs, the distribution of the DGs, and the load, influence the maximum DG capacity. Calculation of the maximum capacity of DGs versus the system length indicates that the constraints can be subdivided into two modes in the conventional SVR and four modes in the reverse power flow SVR. The maximum DG capacity in the system with a reverse power flow SVR is larger than that in a system with the conventional SVR. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 165(4): 41–51, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20591 相似文献
84.
K Kubota M Makuuchi K Kusaka T Kobayashi K Miki K Hasegawa Y Harihara T Takayama 《Canadian Metallurgical Quarterly》1997,26(5):1176-1181
The respective volumes of hepatic tumors and nontumorous parenchyma of 50 patients requiring hepatectomy of more than one segment of Healey for tumor removal were measured using computed tomography (Vol-CT). The volume estimated by Vol-CT was found to correlate with the real weight resected (P < .0001) with a mean absolute error of 64.9 mL. The ratio of the nontumorous parenchymal volume of the resected liver to that of the whole liver (R2) in 15 patients who underwent right or extended right hepatic lobectomy was 43% +/- 15%. Eight of 15 patients with R2s < 60% underwent the procedures without right portal vein embolization (PE). The other seven with R2s exceeding 60% or an indocyanine green retention rate after 15 minutes (ICG15) of 10% to 20% underwent PE: in six of seven, the nontumorous parenchyma of the right hepatic lobe became atrophic and in all seven, the volume of the remaining left hepatic lobe increased with a decrease in the mean R2 from 62% +/- 14% to 55% +/- 8% (P = .0006). In the remaining 35 who underwent other hepatectomy procedures, R2s also remained <60%. Overall, at surgery, in 27 with normal liver function (ICG15 < 10%), R2s exceeded 60% in one, remained at 50% to 60% in five, and <50% in 21, whereas 23 patients except for one with an ICG15 exceeding 10%, had R2s of <50%. The postoperative serum total bilirubin levels in 84% of the patients remained within the normal range and there was no surgery-related mortality. In conclusion, 1) Vol-CT can accurately assess the extent of liver resection, 2) individuals with normal liver function can undergo resection of up to 60% of the nontumorous parenchyma without the need for PE, and 3) PE can be used to reduce the size of the resected tissue and increase the volume of the remnant liver to approximate the target limits in individuals with large tumors or minimally abnormal liver function. 相似文献
85.
Far-infra-red photoconductivity measurements are used to study residual shallow donor species in InP bulk crystals grown by the synthesis, solute-diffusion technique. The observation of 1s-2p, m =+ 1 Zeeman transitions between the shallow donor-impurity states reveals that two dominant residual donors are included in the InP bulk crystals having carrier concentrations of less than 1 × 1015 cm?3 The donors are tentatively identified as Si and S. 相似文献
86.
Tsuyoshi Kawai Akihiro Kubota Kensuke Kawamura Hiroyuki Tsumatori Takuya Nakashima 《Thin solid films》2008,516(9):2666-2669
Diffusion kinetics of three dyes in nematic liquid crystals are studied with single-molecule fluorescence autocorrelation spectroscopy. Markedly large anisotropy was observed in the diffusion coefficient and structure of diffusion molecules showed no marked effect on the anisotropy. 相似文献
87.
A polarisation-independent microring resonator filter is proposed using a birefringent polymer overlay. The thickness of the polymer overlay is optimally designed and the polarisation-independent operation successfully demonstrated 相似文献
88.
In long distribution systems, Step Voltage Regulators (SVRs) are installed to regulate the system voltage. There are some papers on finding optimal placements of SVRs in the system. However, there is no analytic method that focuses on the voltage margin, that is, the optimal placement with respect to the system voltage. The authors propose a method of finding the placement of an SVR so that the voltage margin from the upper (or lower) voltage limit is the largest under heavy load. In order to deal with sets of loads that are dispersed over the entire distribution line, we derive the differential equation of the complex power and that of the voltage drop, which are expressed as functions of distance from a substation. The voltage profile is obtained as a cubic equation by solving the voltage equation if the load distribution is trapezoidal. The method of finding the optimal SVR placement distinguishes three modes with three different voltage profiles. One is the case in which the transformation ratio of the SVR is small and the system length is short, one is the case in which the transformation ratio of the SVR is large and the system length is short, and the third is the case in which the transformation ratio of the SVR is large and the system length is long. The optimal placement and tap position of the SVR are calculated by solving the above‐mentioned equations in these three modes. It is confirmed that the proposed analytical method is appropriate by model calculation results. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 158(4): 11–21, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20481 相似文献
89.
采用无偏振片反射式LCD及超低功耗驱动技术制造移动显示器件 总被引:1,自引:1,他引:0
Kiyoshi Minoura Yasushi Asaoka Eiji Satoh Takashi Satoh Ichiro Ihara Sayuri Fujiwara Akio Miyata Yasuhisa Itoh Seijiro Gyoten Noboru Matsuda Yasushi Kubota 代永平 《现代显示》2010,(7):5-9,35
我们通过对材料和制备条件的精细化处理,生产出一种在低刷新频率下无闪烁和图像迟滞现象的反射式显示器。该显示器的功耗非常低,且可在宽温度范围内工作,是未来移动显示器件的潜力平台。 相似文献
90.
Further Investigations on the Promoting Effect of Mesoporous Silica on Base-Catalyzed Aldol Reaction
Y. Kubota H. Yamaguchi T. Yamada S. Inagaki Y. Sugi T. Tatsumi 《Topics in Catalysis》2010,53(7-10):492-499
Addition of an ordered mesoporous silica to a mixture of an aldol reaction, comprising 4-nitrobenzaldehyde with acetone catalyzed by organic amines, caused significant increase in the reaction rate to afford the β-hydroxyketone in high yield. A cooperative effect between the surface silanol and amine was considered to be the likely reason for the rate-enhancement, which was supported by FTIR spectroscopy. 相似文献